I need to know what size injectors to run for this setup

motor:
355 sbc
flat top pistons
vortec heads
cam:
Basic Operating RPM Range 1,600-5,600
Intake Duration at 050 inch Lift - 215
Exhaust Duration at 050 inch Lift- 224
Duration at 050 inch Lift 215 int./224 exh.
Advertised Intake Duration 268
Advertised Exhaust Duration 279
Advertised Duration 268 int./279 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.489 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.489 in.
Valve Lift with Factory Rocker Arm Ratio 0.489 int./0.489 exh.
Lobe Separation (degrees) 112

Injectors right now are 55lb with 13 psi
this motor is estimated by the machine shop to have at least 300 hp if not a little more

Can I run 80# injectors with stock 13psi and have enough fuel to support this?

I have an EBL flash so tuning is not a problem

I used this link http://www.gtsparkplugs.com/InjectorSizeCalc.html to check but i want to check with you all who know way more than i do about fueling.

Thanks